Two nominees to the National Labor Relations Board were both the problem and solution to the Senate’s flirtation with a major change to its age-old rules.

The wider debate over lowering the vote threshold for executive branch nominees from 60 votes to 51 votes involved seven of President Barack Obama’s nominees, including those to the Labor Department and the Environmental Protection Agency. But once senators got into serious negotiations, the true sticking point was revealed: a pair of NLRB members who were appointed by Obama during recess.

Republicans and lower courts have called the appointments of Sharon Block and Richard Griffin unconstitutional and illegal; the Supreme Court is set to consider the legality of the appointments this fall. But until then, there was no way the GOP was going to settle for Senate approval of nominees they believe were legally dubious, forcing Democrats to back off their fierce opposition to pulling the plug on Block and Griffin’s confirmation.

In return, Senate Majority Leader Harry Reid (D-Nev.) agreed, for now, not to pursue the nuclear option of changing Senate rules by a majority vote, and in turn, several Republicans joined Democrats to confirm Richard Cordray to lead the Consumer Financial Protection Bureau on Tuesday.

Nominees to head the Labor Department, Export-Import Bank and EPA will follow in the coming days, Reid said, as will two new NLRB members.

Obama will nominate AFL-CIO Associate General Counsel Nancy Schiffer and Kent Hirozawa, chief counsel to the NLRB chairman, instead of Block and Griffin. In return for their acquiescence to Republicans’ replacement requests, Democrats get a new talking point: a “fully functioning” NLRB all the way through Obama’s presidency. They also got a couple of picks that Democratic sources said were made in consultation with the AFL-CIO.

“Republicans have insisted on the president’s nominating new people. And he’s done that. It’s a right they had, and this is a compromise,” Reid said before pulling the nominations on Tuesday afternoon. “When the Senate confirms them, the NLRB once again will have a full team to protect the right of American workers.”

The concept had been on the table previously. Minority Leader Mitch McConnell (R-Ky.) said he struck up discussions with Vice President Joe Biden two weeks ago “and suggested that the way out of the dilemma that seemed to be heading our way was to send up two new nominees.” McConnell said he was happy with the result.

But Democrats see a win here, because in addition to guarantees that the GOP will quickly help Democrats confirm Schiffer and Hirozawa before the NLRB ceases to function in August, they also got an agreement not to block another NLRB slot in 2014.

Even with the nuclear option off the table, there’s no guarantee that things will get any easier after the NLRB breakthrough. Tough votes loom for B. Todd Jones’s nomination to lead the Bureau of Alcohol, Tobacco, Firearms and Explosives; North Carolina Rep. Mel Watt for a top housing post; and Homeland Security Secretary Janet Napolitano’s successor.

Still, the progress on the NLRB was enough to turn even the staunchest defenders of Block and Griffin into fans of the deal cut by Reid.

Sen. Tom Harkin (D-Iowa), chairman of the committee that oversees the NLRB, said on Monday night that “it would be grossly unfair to throw them out simply to make a deal” and that he will challenge any bargain that does. On Tuesday, he stood down.

“I think we’ve made a good bargain; it’s a good deal,” Harkin said. “We have a guarantee that for the remainder of Barack Obama’s term, we’ll have a fully functioning NLRB.”

Harkin’s committee will hold hearings on Schiffer and Hirozawa next Tuesday, and the Senate might move toward confirming the new nominees by late next week, Reid said. It was a remarkable turnaround that had senior Democrats lamenting things didn’t turn out better for Griffin and Block.

“I have mixed feelings. I feel badly for those two because they’ve done nothing wrong,” said Majority Whip Dick Durbin of Illinois. “No one has ever questioned their competence or honesty. So occasionally, … people need to be replaced in order to keep moving forward.”

“I care a lot about these two people,” Washington Sen. Patty Murray said. “We all recognize that it’s important to have a functioning NLRB for the broader issues that are out there.”

Aides privately quipped that Democrats got the better of the haggling. But Republicans see it differently: They stood tall in the face of Big Labor to deny two nominees that just a few hours ago Democrats indicated they would simply not bend on.

“The president’s going to send us two new names. That’s what we asked for. I don’t know how we caved,” said North Carolina Sen. Richard Burr. “We just said, ‘You can’t take two people the courts said were unconstitutionally appointed and reappoint them.’”

North Dakota Sen. John Hoeven said that by striking the deal, Democrats tacitly admitted the appointments were “illegal.”

Republicans have long been wary of the NLRB, especially the board’s filing of a lawsuit against Boeing alleging a new plant in right-to-work South Carolina was located in retaliation for union involvement with its Washington state plant. But conservative groups are backing McConnell’s negotiations and swallowing the Senate’s deal to avert a rules change — even if it means confirmation of nominees they oppose and their archrival, the AFL-CIO, getting a chance to pick two new nominees.

“Am I thrilled that some of these people are going to get confirmed because of this? Absolutely not,” said Judson Phillips of Tea Party Nation. “But we can stomp our feet, be rude and belligerent, and Harry Reid can still change the rules. So what’s the point? This is one case when you have to fight smart.”

And unlike a Senate immigration bill that riled up conservatives across the country, this one might be too deep in the weeds for the tea party bloc of the Republican Party.

“I don’t think this is something that is going to mobilize the grass roots,” said Tea Party Express Chairwoman Amy Kremer. “I don’t want to call it a win. It’s what it is, and we did avert the nuclear option.”

Tarini Parti, John Bresnahan and Anna Palmer contributed to this report.